Case 1: A 48-year-old woman presented with acute dizziness and unsteady gait developed head titubation, repeated language and calculation impairment. Her neural antibodies were negative with commercial kits. Further investigation showed serum and CSF “Medusa head” staining pattern of Purkinje cell in rat cerebellum. An in-house cell-based assay proved the existence of anti-mGluR1 antibodies. One-year follow-up revealed serum antibodies titers dramatically decreased and CSF antibodies negative after using steroids and intravenous immunoglobulin, but still left prominent cerebellum atrophy and severe cerebellar deficits.
Case 2: Two years ago, a 61-year-old man presented with painless nasal defects of right eye, photopsia and progressed to 1m/FC within 3 days. A similar episode happened 7 months ago in his left eye. Prior malignancy including renal carcinoma and lung adenocarcinoma discovered seven and four months ago, respectively. On admission, visual acuities were OD 50cm/FC and OS 1m/FC. There was a right RAPD. MRI showed bilateral optic nerves atrophy. Serum AQP4, MOG and paraneoplastic antibodies were all negative. ITPR1 antibodies were proved by tissue-based assay and Euroimmun cell-based assay. He didn’t accept immunotherapies and was discharged.